<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
	</body>
    <script>
    (function(){
        //设置cookie
        function setCookie(c_name,val){
            var acTime = new Date();
            //有效期为1分钟
            acTime.setTime(acTime.getTime()+1*60*1000);
            document.cookie=c_name+"="+escape(val)+";expires="+acTime.toGMTString();
        }
        //获取cookie
        function getCookie(c_name){
            if(document.cookie.length>0){
                c_start = document.cookie.indexOf(c_name+"=");
                if(c_start!=-1){
                    c_start=c_start+c_name.length+1;
                    c_end = document.cookie.indexOf(';',c_start);
                    if(c_end==-1){
                        c_end=document.cookie.length;
                        return unescape(document.cookie.substring(c_start,c_end));
                    }
                }
            }
            return "";
        }    
        //检查cookie
        function checkCookie(){
            username = getCookie('username');
            if(username!=null&&username!=""){
                alert("欢迎"+username);
            }else{
                username = prompt("请输入名字","");
                if(username!=null&&username!=""){
                    setCookie('username',username);
                }
            }
        }
        checkCookie();
    })();
    </script>
</html>